1. Field of Invention
The present invention relates generally to cartridge storage systems for handling and storing cartridges, such as optical disk or magnetic tape cartridges, and more specifically, to a system and method for supplying power and control signals to a movable device (i.e., a cartridge access device) that stores and retrieves cartridges in a cartridge storage system.
2. Related Art
Many different types of cartridge storage and handling systems exist and are being used to store data cartridges (and other types of cartridges) at known locations and to retrieve desired cartridges so that data may be written to and/or read from the data cartridges. Such data storage and handling systems are often referred to as xe2x80x9cautochangersxe2x80x9d or xe2x80x9cjuke boxxe2x80x9d data storage systems, particularly if they accommodate a large number of individual data cartridges.
A typical juke box data storage system includes one or more different types of cartridge-receiving devices for holding the various data cartridges. For example, one type of cartridge-receiving device may comprise a cartridge storage rack or xe2x80x9cmagazinexe2x80x9d while another type of cartridge-receiving device may comprise a cartridge read/write device. The cartridge storage racks or magazines serve to provide storage locations for the data cartridges and are commonly arranged so that they form one or more vertical stacks. The cartridge read/write device may be located adjacent the cartridge stack, although the cartridge read/write device can be positioned at any convenient location. The data storage system may also include a cartridge access device for accessing the various data cartridges contained in the cartridge-receiving devices and a positioning device for moving the cartridge access device among the cartridge-receiving devices.
If a host computer system issues a request for data contained on a particular data cartridge, a control system associated with the cartridge access device actuates the positioning system to move the cartridge access device along the cartridge storage rack until the cartridge access device is positioned adjacent the desired data cartridge. The cartridge access device then removes the data cartridge from the cartridge storage rack and carries it to the cartridge read/write device. The cartridge access device inserts the selected data cartridge into the cartridge read/write device so that the host computer may thereafter read data from or write data to the data cartridge. After the read/write operation is complete, the cartridge access device removes the data cartridge from the read/write device and returns it to a specified location in the cartridge storage rack.
Most cartridge access devices have components that require both power and control signals. For example, the positioning system that moves the cartridge access device to the appropriate location usually requires power and control signals in order to appropriately move the cartridge access device.
A simple technique for providing the power and control signals to the cartridge access device is to connect a power cable and a control cable to the cartridge access device, as is commonly done in the prior art. The power cable supplies the components of the cartridge access device with power, and the control cable provides the cartridge access device with control signals for proper operation. Both the power cable and the control cable can be. tied together or integrated into a single cable.
However, if the cables are not properly secured, the cables can interfere with the motion of the cartridge access device. For example, the cables can block the path of movement of the cartridge access device causing the cartridge access device to malfunction or jam. Alternatively, the cables can wrap around the cartridge access device as the cartridge access device moves in different directions thereby impeding the motion of the cartridge access device or interfering with the retrieval of the data cartridge.
Furthermore, having a cable coupled to the moving cartridge access device can make it more difficult to manufacture and service the data storage system. In this regard, the cable can interfere with efforts to install, remove, and access the cartridge access device and other components in the system. In addition, communicating signals through the cable can adversely emit radio frequency interference (RIF) from the cable. Other problems associated with having a cable coupled to a moving cartridge access device should be apparent to one ordinarily skilled in the art.
Thus, a heretofore unaddressed need exists in the industry for a system and method of providing power and/or control signals to a movable cartridge access device within a data storage system without disrupting the motion of the cartridge access device.
The present invention overcomes the inadequacies and deficiencies of the prior art as discussed herein. Generally described, the present invention provides a system and method for providing power and control signals to a movable device that retrieves and stores cartridges within a cartridge storage system without connecting a power cable to the movable device.
The present invention utilizes a frame assembly, an engaging member, a conductive member, and a cartridge access device. The frame assembly has a channel or groove. The conductive member is attached to a surface of the frame assembly and extends through the channel of the frame assembly. The cartridge access device receives and transports cartridges from one location within the cartridge storage system to another location within the cartridge storage system. The first engaging member is coupled to the cartridge access device and engaged with the conductive member. The engaging member is conductive so that electrical signals can be passed between the engaging member and the conductive member attached to the frame assembly.
In accordance with another feature of the present invention, the engaging member includes a shaft, a brush, a rod, and a spring. The brush is coupled to the rod which is inserted into a hole in the shaft. The spring is coupled to the rod and engaged with the shaft so that a force generated by the spring tends to push the brush away from the shaft and toward the conductive member. Due to the force generated by the spring, the brush engages the conductive member and maintains contact with the engaging member (i.e., slides across a surface of the engaging member) as the cartridge access device moves.
In accordance with another feature of the present invention, control signals are superimposed on a power signal that is supplied to the cartridge access device via the conductive member and the engaging member. A filter is designed to filter out the power signal from the control signals so that the control signals can be recovered and utilized by the cartridge access device in order to operate the components of the cartridge access device.
The present invention can also be viewed as providing a method for transferring data cartridges within a data storage system. Briefly described, the method can be broadly conceptualized by the following steps: inserting a cartridge associated with the cartridge storage system into a cartridge access device; moving the cartridge access device; sliding a brush coupled to the cartridge access device across a surface of the conductive member during the moving step; and supplying the cartridge access device with electrical power via the brush and the conductive member.
The present invention has many advantages, a few of which are delineated hereafter, as mere examples.
An advantage of the present invention is that electrical power can be supplied to components of a cartridge access device within a data storage system without connecting a power cable to the cartridge access device.
Another advantage of the present invention is that control signals can be supplied to the cartridge access device without connecting a control cable to the cartridge access device.
Another advantage of the present invention is that the cartridge access device can move through the data storage system without interference from a power cable or a control cable.
Another advantage of the present invention is that radio frequency interference (RIF) associated with a cartridge storage system can be reduced.
Another advantage of the present invention is that the cartridge access device with the cartridge storage system can be easier to access and to install.